If a material is very nearly isotropic, quantifying the residual
anisotropy may be quite difficult using methods such as pulse superposition or
neutron scattering, when only a small sample is available. However, resonant
ultrasound spectroscopy using piezoelectric film transducers allows precise
(<0.1%) measurement of elastic constants even on very small (<0.25 mg), fragile
samples. This is of interest in the study of icosahedral quasicrystals, which
should theoretically be isotropic, but have closely related phases which are
crystalline. Results on several samples of quasicrystalline and cubic AlCuLi
will be presented, and use of rotations of the elastic tensor and Monte Carlo
style error simulations to aid in the data analysis will be discussed. [Work
supported by NSF Grant No. DMR-9306791 and by ONR.]